Two-dimensional analysis for CuxS-CdS solar cells with nonuniform skin region

Due to rapid diffusion of externally applied copper along the disordered region of the grain boundaries, the skin region of the Cu
x
S-CdS solar cell consists of alternate layers of thick and thin regions of p-Cu
x
S. A two-dimensional idealized analysis leading to the short-circuit current, open-circuit voltage, conversion efficiency and spectral response of the cell is presented. For a typical cell, the variations of these parameters with grain size and width of the disordered regions are shown. It was pointed out that for such a cell, there is an optimum crystallite size for maximum conversion efficiency of the cell. The spectral response characteristics shows a relative improvement in the low-frequency side with increase in density of the CdS crystallites. This is probably due to the vertical junctions formed at the disordered regions.